Determination of the Compound Biological Effectiveness (CBE) Factors Based on the <i>ISHIYAMA-IMAHORI</i> Deterministic Parsing Model with the Dynamic PET Technique

Abstract

Purpose: In defining the biological effects of the 10 B( n , α ) 7 Li neutron capture reaction, we have proposed a deterministic parsing model ( ISHIYAMA-IMAHORI model) to determine the Compound Biological Effectiveness ( CBE ) factor in Borono-Phenyl-Alanine ( BPA )-mediated Boron Neutron Capture Therapy ( BNCT ). In present paper, we demonstrate a specific method of how the application of the case of application to actual patient data , which is founded on this model for tissues and tumor. Method: To determine the CBE factor, we derived the following new calculation formula founded on the deterministic parsing model with three constants, CBE 0 , F , n and the eigen value N th /N max . (1), where, N th and N max are the threshold value of boron concentration of N and saturation boron density and CBE 0 , F and n are given as 0.5, 8 and 3, respectively. In order to determine N th and N max in the formula, sigmoid logistic function was employed for 10 B concentration data, D b ( t ) obtained by dynamic PET technique. (2), where, A , a and t 0 are constants. Results and Conclusion: From the application of sigmoid function to dynamic PET data, it is concluded that the N th and N max for tissue and tumor are identified with the parameter constants in the sigmoid function in Equation (2) as: (3). And the calculated CBE factor values obtained from Equation (1), with N th /N max .